1. Field of the Invention
The present invention relates to a determination circuit.
2. Description of the Related Art
Many of recently popular mobile devices are provided with ports connected to, for example, Micro-USB (Universal Serial Bus) plugs (see. e.g., Japanese Laid-Open Patent Publication No. 2010-205437). These ports are connected with plugs for Micro-USB (hereinafter simply referred to as plugs) from devices such as a personal computer and a charger.
The plugs are generally provided with a terminal where information (identification information) of a type of a device, etc., appears, specifically, an identification terminal having a resistor for identification connected between the terminal and the ground. Thus, if a plug is connected to a mobile device, the mobile device acquires identification information, thereby being able to identify a type of the device connected to the mobile device, and the like.
However, in some devices such as a charger, etc., a resistance value indicative of a type of a device may be set at a predetermined terminal (e.g., a terminal for data communication) different from the identification terminal. Recently, as the types of chargers have been increased, various values have been used as resistance values of the predetermined terminals of the plugs. As a result, a mobile device may not determine a connected device correctly.